Comment by audunw

For the booster I think it’s fairly well established that it’s cheaper to reuse it. It’s not that hard on a booster to come down again, and it doesn’t seem like it’s that much work for SpaceX to refurbish their boosters.

For the upper stage it still remains to be seen. Having the upper stage return from orbit is a lot harder, as we’re seeing with the Starship. You need a lot of thermal protection. Maybe flaps depending on the design.

Jeff Bezos mentioned in a recent interview that for the upper stage they’re working on a reusable and a cost reduced version of the upper stage in parallell. They can’t determine yet which will end up being cheaper. That tells you something about how hard it is to do second stage reuse.

Rocket Lab has shown with the Neutron rocket what’s possible if you’re really innovative with optimising for cost on the second stage. Their second stage will probably be cheaper than the satellites they send to orbit